1. Field of the Invention
The present invention relates to systems and methods for protecting the unauthorized dissemination of data, and in particular to a system and method for watermarking data for later forensic retrieval.
2. Description of the Related Art
Movie studios and other owners of the intellectual property in media programs such as movies, television programs, audio programs and the like have been attempting, without success, to mandate the use of watermarking to aid forensic analysis of pirated materials.
Digital watermarking is one technique that can help protect such intellectual property. Digital watermarking is a process by which information in the signal itself can be used to verify the authenticity or identity of the owners or to trace the source of a media program. Watermarking may include visible or invisible watermarking. With visible watermarking, the information discernable in the media program without special equipment. An example of a digital watermark is a logo or bug that might be placed in the corner of one or more frames of the media program. With invisible watermarking, the information is added to the media program in such a way that it cannot be easily perceived without special equipment.
Watermarking can prevent unauthorized copying or distribution of media programs in two ways. First, a watermark can be inserted into the media program, and retrieved and examined before any copy of the media program is permitted. In this example, if the watermark cannot be retrieved, or if the retrieved watermark indicates that copying is not permitted, copying is disabled. Second, a watermark may also allow the owner to perform source tracing to determine where the unauthorized copy was procured. In this system, a watermark is embedded into the media program at each point of distribution or copying. If an unauthorized copy of the work is later found, the watermark(s) may be retrieved, and the chain of distribution can be identified back to the source of the unauthorized copy.
To date, several companies have marketed watermarking technologies but without much success in the market due to several significant technical and economic reasons such as design complexity and high operational overhead. For these reasons, the broadcasters of such media programs have not adopted watermarking technologies even though those who own the intellectual property are pushing strongly for adoption of a solution. A simple, low cost, and near zero broadcast infrastructure impact design can address this problem.
The current providers of watermarking technology either have (1) large clients disposed at the headend (transmitting facility) and lighter set top box (STB) or receiver software kernels at the subscriber facility or (2) lighter headend clients with larger and more sophisticated STB kernel clients. In either case there is a high level of complexity and cost to gather identifiable forensic data. Some of these complexities include finding the appropriate space in the video to insert the data while keeping the watermark as invisible as possible so as to avoid disrupting the viewing experience, redesigning the broadcasters headend to integrate a set of watermarking servers and adding a large software kernel to the STB code and re-qualify the STB code to verify correct operation of new and old functionality. In some current watermarking designs after the broadcast and STB systems are re-designed there are sophisticated retrieval process and procedures needed to be developed to capture the data from pirated materials in order to recover the forensic data.
All of these systems come at a high cost. Some watermarking companies require payment of substantial fees such as Non-Recurring Engineering (NRE) effort fees to obtain or use the required headend client, STB kernel client and forensic retrieval clients. They also require fees for keying materials or per usage licenses. All of which are burdensome to the broadcaster/customer.
What is needed is a system and method for securely and effectively watermarking media programs at a reduced cost. The present invention satisfies that need.